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Kumar R, Sinha NR, Mohan RR. Corneal gene therapy: Structural and mechanistic understanding. Ocul Surf 2023; 29:279-297. [PMID: 37244594 DOI: 10.1016/j.jtos.2023.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Cornea, a dome-shaped and transparent front part of the eye, affords 2/3rd refraction and barrier functions. Globally, corneal diseases are the leading cause of vision impairment. Loss of corneal function including opacification involve the complex crosstalk and perturbation between a variety of cytokines, chemokines and growth factors generated by corneal keratocytes, epithelial cells, lacrimal tissues, nerves, and immune cells. Conventional small-molecule drugs can treat mild-to-moderate traumatic corneal pathology but requires frequent application and often fails to treat severe pathologies. The corneal transplant surgery is a standard of care to restore vision in patients. However, declining availability and rising demand of donor corneas are major concerns to maintain ophthalmic care. Thus, the development of efficient and safe nonsurgical methods to cure corneal disorders and restore vision in vivo is highly desired. Gene-based therapy has huge potential to cure corneal blindness. To achieve a nonimmunogenic, safe and sustained therapeutic response, the selection of a relevant genes, gene editing methods and suitable delivery vectors are vital. This article describes corneal structural and functional features, mechanistic understanding of gene therapy vectors, gene editing methods, gene delivery tools, and status of gene therapy for treating corneal disorders, diseases, and genetic dystrophies.
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Affiliation(s)
- Rajnish Kumar
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow campus, UP, 226028, India
| | - Nishant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA
| | - Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
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Sarkar S, Panikker P, D’Souza S, Shetty R, Mohan RR, Ghosh A. Corneal Regeneration Using Gene Therapy Approaches. Cells 2023; 12:1280. [PMID: 37174680 PMCID: PMC10177166 DOI: 10.3390/cells12091280] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 04/13/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
One of the most remarkable advancements in medical treatments of corneal diseases in recent decades has been corneal transplantation. However, corneal transplants, including lamellar strategies, have their own set of challenges, such as graft rejection, delayed graft failure, shortage of donor corneas, repeated treatments, and post-surgical complications. Corneal defects and diseases are one of the leading causes of blindness globally; therefore, there is a need for gene-based interventions that may mitigate some of these challenges and help reduce the burden of blindness. Corneas being immune-advantaged, uniquely avascular, and transparent is ideal for gene therapy approaches. Well-established corneal surgical techniques as well as their ease of accessibility for examination and manipulation makes corneas suitable for in vivo and ex vivo gene therapy. In this review, we focus on the most recent advances in the area of corneal regeneration using gene therapy and on the strategies involved in the development of such therapies. We also discuss the challenges and potential of gene therapy for the treatment of corneal diseases. Additionally, we discuss the translational aspects of gene therapy, including different types of vectors, particularly focusing on recombinant AAV that may help advance targeted therapeutics for corneal defects and diseases.
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Affiliation(s)
- Subhradeep Sarkar
- GROW Research Laboratory, Narayana Nethralaya Foundation, Bangalore 560099, Karnataka, India
- Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Priyalakshmi Panikker
- GROW Research Laboratory, Narayana Nethralaya Foundation, Bangalore 560099, Karnataka, India
| | - Sharon D’Souza
- Department of Cornea and Refractive Surgery, Narayana Nethralaya, Bangalore 560010, Karnataka, India
| | - Rohit Shetty
- Department of Cornea and Refractive Surgery, Narayana Nethralaya, Bangalore 560010, Karnataka, India
| | - Rajiv R. Mohan
- Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 65201, USA
- One-Health Vision Research Program, Departments of Veterinary Medicine and Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA
- Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO 65211, USA
| | - Arkasubhra Ghosh
- GROW Research Laboratory, Narayana Nethralaya Foundation, Bangalore 560099, Karnataka, India
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Weiss JS, Willoughby CE, Abad-Morales V, Turunen JA, Lisch W. Update on the Corneal Dystrophies-Genetic Testing and Therapy. Cornea 2022; 41:1337-1344. [PMID: 36219210 DOI: 10.1097/ico.0000000000002857] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/07/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT One major purpose of the IC3D Corneal Dystrophy Nomenclature Revision was to include genetic information with a goal of facilitating investigation into the pathogenesis, treatment, and perhaps even prevention of the corneal dystrophies, an ambitious goal. Over a decade has passed since the first publication of the IC3D Corneal Dystrophy Nomenclature Revision. Gene therapy is available for an early-onset form of inherited retinal degeneration called Leber congenital amaurosis, but not yet for corneal degenerations. We review the current state of affairs regarding our original ambitious goal. We discuss genetic testing, gene therapy [RNA interference (RNAi) and genome editing], and ocular delivery of corneal gene therapy for the corneal dystrophies. Why have gene therapy techniques not yet been introduced for the corneal dystrophies?
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Affiliation(s)
- Jayne S Weiss
- Department of Ophthalmology, Pathology and Pharmacology, Louisiana State University School of Medicine, New Orleans, LA
| | - Colin E Willoughby
- Genomic Medicine, Biomedical Sciences Research Institute, Ulster University, Coleraine, Northern Ireland, United Kingdom
| | - Víctor Abad-Morales
- Fundació de Recerca de l'Institut de Microcirurgia Ocular, Barcelona, Spain
- Department of Genetics, Institut de Microcirurgia Ocular (IMO), Barcelona, Spain; Dr. Abad-Morales is now with the SpliceBio, Barcelona, Spain, Barcelona, Spain
| | - Joni A Turunen
- Department of Ophthalmology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Helsinki, Finland; and
| | - Walter Lisch
- Department of Ophthalmology, University Medical Center of the Johannes Gutenberg, University Mainz, Mainz, Germany
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Evaluation of CRISPR/Cas9 mediated TGIF gene editing to inhibit corneal fibrosis in vitro. Exp Eye Res 2022; 220:109113. [PMID: 35588782 DOI: 10.1016/j.exer.2022.109113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 04/22/2022] [Accepted: 05/10/2022] [Indexed: 11/23/2022]
Abstract
Corneal wound healing is influenced by many factors including transcriptional co-repressors and co-activators. Interactions of co-activators and co-repressors with Smads influence mechanistic loop facilitating transcription of alpha-smooth muscle actin (α-SMA), a key profibrotic gene, in corneal repair. The role of a transcriptional repressor, 5'TG3'-interacting factor (TGIF), in the regulation of α-SMA and myofibroblast formation in the cornea was shown previously by our group. This study tested a hypothesis if TGIF1 gene editing via CRISPR/Cas9 can ease myofibroblast formation in the cornea using an in vitro model. Primary human corneal stromal fibroblasts (hCSFs) generated from donor corneas received gene-editing plasmid facilitating loss (CRISPR/Cas9 knockout) or gain (CRISPR activation) of TGIF function by UltraCruz transfection reagent. Phase-contrast microscopy, immunoblotting, immunocytochemistry and quantitative polymerase chain reaction (qPCR) were used to measure levels of myofibroblast profibrotic genes (α-SMA, fibronectin, Collagen-I, and Collagen-IV) in hCSFs lacking or overexpressing TGIF1 after growing them in± transforming growth factor beta1 (TGF-β1) under serum-free conditions. The CRISPR-assisted TGIF1 activation (gain of function) in hCSFs demonstrated significantly decreased myofibroblast formation and messenger ribonucleic acid (mRNA) and protein levels of profibrotic genes. Conversely, CRISPR/Cas9-assisted TGIF knockdown (loss of function) in hCSFs demonstrated no significant change in the levels of myofibroblast formation or profibrotic genes under similar conditions. These results suggest that TGIF gene-editing approach can be employed to modulate the transcriptional activity of α-SMA in controlling pathological and promoting physiological wound healing in an injured cornea.
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Mohan RR, Martin LM, Sinha NR. Novel insights into gene therapy in the cornea. Exp Eye Res 2021; 202:108361. [PMID: 33212142 PMCID: PMC9205187 DOI: 10.1016/j.exer.2020.108361] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 11/07/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022]
Abstract
Corneal disease remains a leading cause of impaired vision world-wide, and advancements in gene therapy continue to develop with promising success to prevent, treat and cure blindness. Ideally, gene therapy requires a vector and gene delivery method that targets treatment of specific cells or tissues and results in a safe and non-immunogenic response. The cornea is a model tissue for gene therapy due to its ease of clinician access and immune-privileged state. Improvements in the past 5-10 years have begun to revolutionize the approach to gene therapy in the cornea with a focus on adeno-associated virus and nanoparticle delivery of single and combination gene therapies. In addition, the potential applications of gene editing (zinc finger nucleases [ZNFs], transcription activator-like effector nucleases [TALENs], Clustered Regularly Interspaced Short Palindromic Repeats/Associated Systems [CRISPR/Cas9]) are rapidly expanding. This review focuses on recent developments in gene therapy for corneal diseases, including promising multiple gene therapy, while outlining a practical approach to the development of such therapies and potential impediments to successful delivery of genes to the cornea.
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Affiliation(s)
- Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-health Vision Research Center, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, United States.
| | - Lynn M Martin
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-health Vision Research Center, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Nishant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-health Vision Research Center, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
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